/*全局设置*/
* {
    padding: 0px;
    margin: 0px;
    margin:0 auto;
   
}
#btn1{
	margin: 10px;
	
}
td{
	width:300px;
	height: 50px;
	}

#dd{
	margin-top:50px;
	height:150px;
	width: 900px;
}


#btn2{
	margin-left:48%;
}

span{
	color: red;
}